My Question:Will running LinuxMCE for the first time thrash my currently working Mythtv setup ? I want to use my satellite setup within LinuxMCE's core and view it using the local director interface Has any one else tired this?

From playing with past LinuxMCE test installs, LinuxMCE seems to have a mind of it own when it comes to it's auto configuration routines. Seems alot going on whenever linuxMCE reloads. As a total Noobe it makes me nervous. Took some reading just to figure out how to make the nvidia driver preference stick

A related Question:How do I create a simple startup script that would initialize and load my dvb 0 and loopback 1 modules prior to the launch of the Mythbackend within LinuxMCE?

there is a myth tv setup section in linuxmce. if you don't touch that i think that you will not erase the original setup. regarding the second question, you should be able to force loading of desired modules by adding them in /etc/modules.

Although I doubt that we should be talking about the sascng module (no legal reason to have it), I would install LinuxMCE first and then recompile mythtv with the patches needed to receive North America fta DVB-s feeds.